Abstract P5-05-04: Intraductal delivery of RNAi-based therapeutics to gene targets identified through computational systems modeling

We utilize a computational systems biology approach to identify gene targets with the potential to serve as targets for therapeutic RNAi. Inferred gene regulatory network models were constructed using whole transcriptome expression profiling for progressive stages of mammary tumorigenesis in FVB C3(1)-SV40Tag mice. These computational models predicted key mediator transcription factors that are critical for hyperplasia and ductal filling in the early stages of disease progression. Putative mediator transcription factors were targeted by RNAi first in a mammary spheroid assay. Based on their ability to restore lumen formation and normal apical-basal polarization to mammary tumor cells, two transcription factors, Hoxa1 and Hoxb13, were selected for validation in vivo. siRNA targeting each of these transcription factors was formulated with lipidoid nanoparticles and delivered to the mammary gland via intraductal injection. Silencing Hoxa1 resulted in a significant reduction in tumor incidence in FVB C3(1)-SV40Tag. This represents a novel strategy to achieve localized silencing of a target gene in the mammary epithelium.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-05-04.

Comparison of two selective media for the recovery of Clostridium difficile from environmental surfaces

Two culture media were compared for their ability to isolate Clostridium difficile from environmental sites within a UK hospital. The media were cefoxitin-cycloserine-egg yolk agar plus lysozyme (CCEY/L) and chromID C. difficile. A wide range of environmental surfaces was sampled using sterile sponges (Polywipes) and these were inoculated on to both media. C. difficile was recovered from 105 of 496 sites (21%) using a combination of both media. The sensitivity of chromID C. difficile was 87.6% compared with 26.6% for CCEY/L (P < 0.0001). chromID C. difficile performed significantly better than CCEY/L for the recovery of C. difficile from the environment.

Evaluation of Preoperative Risk Factors for Converting Laparoscopic to Open Cholecystectomy

Performing laparoscopic cholecystectomy (LC) always carries the risk of having to convert from laparoscopic to open cholecystectomy (LOC). Being able to identify these patients preoperatively may allow better preoperative planning and lowering operative cost. All LC and LOC were performed by the Eastern Virginia Medical School Department of Surgery retrospectively identified between January 2008 and December 2009. Preoperative risk factors identified in both groups included: age, gender, body mass index greater than 30 kg/m2, diabetes mellitus, previous upper abdominal surgery, previous abdominal surgery, presence of pericholecystic fluid, gallbladder wall thickness greater than 3 mm, preoperative diagnosis of acute cholecystitis, and pancreatitis. Reasons for conversion in the LOC group were identified from the operative note. A total of 346 LC and LOC were identified. The LOC group had 41 identified with a conversion rate of 11.9 per cent. The LOC group was compared with 100 randomly chosen LC. Risk factors that reached statistical significance for conversion included advanced age, male gender, previous upper abdominal surgery, preoperative diagnosis of acute cholecystitis, and gallbladder wall thickness greater than 3 mm ( P = 0.0009). Average operative time was higher in LOC compared with open cholecystectomy (123 minutes average vs 109 minutes average). Of the reasons for conversion, the degree of inflammation was the most common (51.2%). Preoperative risk factors that were associated with need for conversion were advanced age, male gender, previous upper abdominal surgery, preoperative diagnosis of acute cholecystitis, and pericholecystitic fluid. In patients who have all of these risk factors, we recommend starting with an open cholecystectomy. This will save operative time and overall cost.

Evaluation of preoperative risk factors for converting laparoscopic to open cholecystectomy

Performing laparoscopic cholecystectomy (LC) always carries the risk of having to convert from laparoscopic to open cholecystectomy (LOC). Being able to identify these patients preoperatively may allow better preoperative planning and lowering operative cost. All LC and LOC were performed by the Eastern Virginia Medical School Department of Surgery retrospectively identified between January 2008 and December 2009. Preoperative risk factors identified in both groups included: age, gender, body mass index greater than 30 kg/m(2), diabetes mellitus, previous upper abdominal surgery, previous abdominal surgery, presence of pericholecystic fluid, gallbladder wall thickness greater than 3 mm, preoperative diagnosis of acute cholecystitis, and pancreatitis. Reasons for conversion in the LOC group were identified from the operative note. A total of 346 LC and LOC were identified. The LOC group had 41 identified with a conversion rate of 11.9 per cent. The LOC group was compared with 100 randomly chosen LC. Risk factors that reached statistical significance for conversion included advanced age, male gender, previous upper abdominal surgery, preoperative diagnosis of acute cholecystitis, and gallbladder wall thickness greater than 3 mm (P = 0.0009). Average operative time was higher in LOC compared with open cholecystectomy (123 minutes average vs 109 minutes average). Of the reasons for conversion, the degree of inflammation was the most common (51.2%). Preoperative risk factors that were associated with need for conversion were advanced age, male gender, previous upper abdominal surgery, preoperative diagnosis of acute cholecystitis, and pericholecystitic fluid. In patients who have all of these risk factors, we recommend starting with an open cholecystectomy. This will save operative time and overall cost.

Homeless in North and West Belfast: an oral health needs assessment

AIM

The aim was to assess the oral health needs of a homeless population residing in North and West Belfast Health and Social Services Trust area, in order to determine levels of unmet need and allow recommendations for service delivery to be made.

METHOD

A sample of single homeless people was gathered using a snowballing sampling technique. Fourteen hostels located in North and West Belfast were visited in tandem with the homeless health care coordinator. All consenting participants were asked to complete a detailed medical history questionnaire and a questionnaire to assess their health and psycho-social needs, dental anxiety and oral health related quality of life. All participants received an oral examination.

RESULTS

Three hundred and seventeen homeless people consented to take part. Two hundred and sixty-seven (84%) were male. Thirty three percent of participants had mental health problems including psychotic illness, depression and anxiety. Forty-three percent of the sample stated they were addicted to alcohol and 3% were registered injecting drug users. Five percent (16) of the sample had soft tissue swellings of which two were found to be oral cancer. The participants had a mean D(3cv)MFT of 16.16 (95% CI: 15.71, 17.46). Seventy-fi ve percent of the sample had bleeding gums and calculus; however only 4%had pocket depths of 6 mm or more. Dental anxiety status was related to dental disease experience which impacted negatively on quality of life. Forty-seven percent of the participants felt at least occasionally self-conscious and/or felt ashamed by the appearance of their teeth.

CONCLUSIONS

Health and psychosocial factors associated with being homeless must be incorporated into the delivery of context-sensitive oral healthcare for this socially excluded population.

Epidemiological survey of Clostridium difficile ribotypes in the North East of England during an 18-month period

During an 18-month period, 1606 stool specimens from laboratory-confirmed cases of Clostridium difficile infection in the North East of England were ribotyped using unrestricted polymerase chain reaction. Of these, 87.6% grew C. difficile on culture; 70% had one of 10 recognizable ribotypes of which 001, 106 and 027 were the most prevalent. The proportions of ribotypes 002 and 015 declined during the study period, whereas ribotypes 016 and 023 increased. Ribotype 005 was significantly more numerous in males and ribotype 027 was associated with significantly higher mean age. Our findings differ from national data derived from more selective testing.